hw/gpio/sifive_gpio.c

   1 /*
   2  * SiFive System-on-Chip general purpose input/output register definition
   3  *
   4  * Copyright 2019 AdaCore
   5  *
   6  * Base on nrf51_gpio.c:
   7  *
   8  * Copyright 2018 Steffen Görtz <contrib@steffen-goertz.de>
   9  *
  10  * This code is licensed under the GPL version 2 or later.  See
  11  * the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "qemu/log.h"
  16 #include "hw/irq.h"
  17 #include "hw/qdev-properties.h"
  18 #include "hw/gpio/sifive_gpio.h"
  19 #include "migration/vmstate.h"
  20 #include "trace.h"
  21
  22 static void update_output_irq(SIFIVEGPIOState *s)
  23 {
  24     uint32_t pending;
  25     uint32_t pin;
  26
  27     pending = s->high_ip & s->high_ie;
  28     pending |= s->low_ip & s->low_ie;
  29     pending |= s->rise_ip & s->rise_ie;
  30     pending |= s->fall_ip & s->fall_ie;
  31
  32     for (int i = 0; i < s->ngpio; i++) {
  33         pin = 1 << i;
  34         qemu_set_irq(s->irq[i], (pending & pin) != 0);
  35         trace_sifive_gpio_update_output_irq(i, (pending & pin) != 0);
  36     }
  37 }
  38
  39 static void update_state(SIFIVEGPIOState *s)
  40 {
  41     size_t i;
  42     bool prev_ival, in, in_mask, port, out_xor, pull, output_en, input_en,
  43         rise_ip, fall_ip, low_ip, high_ip, oval, actual_value, ival;
  44
  45     for (i = 0; i < s->ngpio; i++) {
  46
  47         prev_ival = extract32(s->value, i, 1);
  48         in        = extract32(s->in, i, 1);
  49         in_mask   = extract32(s->in_mask, i, 1);
  50         port      = extract32(s->port, i, 1);
  51         out_xor   = extract32(s->out_xor, i, 1);
  52         pull      = extract32(s->pue, i, 1);
  53         output_en = extract32(s->output_en, i, 1);
  54         input_en  = extract32(s->input_en, i, 1);
  55         rise_ip   = extract32(s->rise_ip, i, 1);
  56         fall_ip   = extract32(s->fall_ip, i, 1);
  57         low_ip    = extract32(s->low_ip, i, 1);
  58         high_ip   = extract32(s->high_ip, i, 1);
  59
  60         /* Output value (IOF not supported) */
  61         oval = output_en && (port ^ out_xor);
  62
  63         /* Pin both driven externally and internally */
  64         if (output_en && in_mask) {
  65             qemu_log_mask(LOG_GUEST_ERROR, "GPIO pin %zu short circuited\n", i);
  66         }
  67
  68         if (in_mask) {
  69             /* The pin is driven by external device */
  70             actual_value = in;
  71         } else if (output_en) {
  72             /* The pin is driven by internal circuit */
  73             actual_value = oval;
  74         } else {
  75             /* Floating? Apply pull-up resistor */
  76             actual_value = pull;
  77         }
  78
  79         if (output_en) {
  80             qemu_set_irq(s->output[i], actual_value);
  81         }
  82
  83         /* Input value */
  84         ival = input_en && actual_value;
  85
  86         /* Interrupts */
  87         high_ip = high_ip || ival;
  88         s->high_ip = deposit32(s->high_ip, i, 1, high_ip);
  89
  90         low_ip = low_ip || !ival;
  91         s->low_ip = deposit32(s->low_ip,  i, 1, low_ip);
  92
  93         rise_ip = rise_ip || (ival && !prev_ival);
  94         s->rise_ip = deposit32(s->rise_ip, i, 1, rise_ip);
  95
  96         fall_ip = fall_ip || (!ival && prev_ival);
  97         s->fall_ip = deposit32(s->fall_ip, i, 1, fall_ip);
  98
  99         /* Update value */
 100         s->value = deposit32(s->value, i, 1, ival);
 101     }
 102     update_output_irq(s);
 103 }
 104
 105 static uint64_t sifive_gpio_read(void *opaque, hwaddr offset, unsigned int size)
 106 {
 107     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
 108     uint64_t r = 0;
 109
 110     switch (offset) {
 111     case SIFIVE_GPIO_REG_VALUE:
 112         r = s->value;
 113         break;
 114
 115     case SIFIVE_GPIO_REG_INPUT_EN:
 116         r = s->input_en;
 117         break;
 118
 119     case SIFIVE_GPIO_REG_OUTPUT_EN:
 120         r = s->output_en;
 121         break;
 122
 123     case SIFIVE_GPIO_REG_PORT:
 124         r = s->port;
 125         break;
 126
 127     case SIFIVE_GPIO_REG_PUE:
 128         r = s->pue;
 129         break;
 130
 131     case SIFIVE_GPIO_REG_DS:
 132         r = s->ds;
 133         break;
 134
 135     case SIFIVE_GPIO_REG_RISE_IE:
 136         r = s->rise_ie;
 137         break;
 138
 139     case SIFIVE_GPIO_REG_RISE_IP:
 140         r = s->rise_ip;
 141         break;
 142
 143     case SIFIVE_GPIO_REG_FALL_IE:
 144         r = s->fall_ie;
 145         break;
 146
 147     case SIFIVE_GPIO_REG_FALL_IP:
 148         r = s->fall_ip;
 149         break;
 150
 151     case SIFIVE_GPIO_REG_HIGH_IE:
 152         r = s->high_ie;
 153         break;
 154
 155     case SIFIVE_GPIO_REG_HIGH_IP:
 156         r = s->high_ip;
 157         break;
 158
 159     case SIFIVE_GPIO_REG_LOW_IE:
 160         r = s->low_ie;
 161         break;
 162
 163     case SIFIVE_GPIO_REG_LOW_IP:
 164         r = s->low_ip;
 165         break;
 166
 167     case SIFIVE_GPIO_REG_IOF_EN:
 168         r = s->iof_en;
 169         break;
 170
 171     case SIFIVE_GPIO_REG_IOF_SEL:
 172         r = s->iof_sel;
 173         break;
 174
 175     case SIFIVE_GPIO_REG_OUT_XOR:
 176         r = s->out_xor;
 177         break;
 178
 179     default:
 180         qemu_log_mask(LOG_GUEST_ERROR,
 181                 "%s: bad read offset 0x%" HWADDR_PRIx "\n",
 182                       __func__, offset);
 183     }
 184
 185     trace_sifive_gpio_read(offset, r);
 186
 187     return r;
 188 }
 189
 190 static void sifive_gpio_write(void *opaque, hwaddr offset,
 191                               uint64_t value, unsigned int size)
 192 {
 193     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
 194
 195     trace_sifive_gpio_write(offset, value);
 196
 197     switch (offset) {
 198
 199     case SIFIVE_GPIO_REG_INPUT_EN:
 200         s->input_en = value;
 201         break;
 202
 203     case SIFIVE_GPIO_REG_OUTPUT_EN:
 204         s->output_en = value;
 205         break;
 206
 207     case SIFIVE_GPIO_REG_PORT:
 208         s->port = value;
 209         break;
 210
 211     case SIFIVE_GPIO_REG_PUE:
 212         s->pue = value;
 213         break;
 214
 215     case SIFIVE_GPIO_REG_DS:
 216         s->ds = value;
 217         break;
 218
 219     case SIFIVE_GPIO_REG_RISE_IE:
 220         s->rise_ie = value;
 221         break;
 222
 223     case SIFIVE_GPIO_REG_RISE_IP:
 224          /* Write 1 to clear */
 225         s->rise_ip &= ~value;
 226         break;
 227
 228     case SIFIVE_GPIO_REG_FALL_IE:
 229         s->fall_ie = value;
 230         break;
 231
 232     case SIFIVE_GPIO_REG_FALL_IP:
 233          /* Write 1 to clear */
 234         s->fall_ip &= ~value;
 235         break;
 236
 237     case SIFIVE_GPIO_REG_HIGH_IE:
 238         s->high_ie = value;
 239         break;
 240
 241     case SIFIVE_GPIO_REG_HIGH_IP:
 242          /* Write 1 to clear */
 243         s->high_ip &= ~value;
 244         break;
 245
 246     case SIFIVE_GPIO_REG_LOW_IE:
 247         s->low_ie = value;
 248         break;
 249
 250     case SIFIVE_GPIO_REG_LOW_IP:
 251          /* Write 1 to clear */
 252         s->low_ip &= ~value;
 253         break;
 254
 255     case SIFIVE_GPIO_REG_IOF_EN:
 256         s->iof_en = value;
 257         break;
 258
 259     case SIFIVE_GPIO_REG_IOF_SEL:
 260         s->iof_sel = value;
 261         break;
 262
 263     case SIFIVE_GPIO_REG_OUT_XOR:
 264         s->out_xor = value;
 265         break;
 266
 267     default:
 268         qemu_log_mask(LOG_GUEST_ERROR,
 269                       "%s: bad write offset 0x%" HWADDR_PRIx "\n",
 270                       __func__, offset);
 271     }
 272
 273     update_state(s);
 274 }
 275
 276 static const MemoryRegionOps gpio_ops = {
 277     .read =  sifive_gpio_read,
 278     .write = sifive_gpio_write,
 279     .endianness = DEVICE_LITTLE_ENDIAN,
 280     .impl.min_access_size = 4,
 281     .impl.max_access_size = 4,
 282 };
 283
 284 static void sifive_gpio_set(void *opaque, int line, int value)
 285 {
 286     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
 287
 288     trace_sifive_gpio_set(line, value);
 289
 290     assert(line >= 0 && line < SIFIVE_GPIO_PINS);
 291
 292     s->in_mask = deposit32(s->in_mask, line, 1, value >= 0);
 293     if (value >= 0) {
 294         s->in = deposit32(s->in, line, 1, value != 0);
 295     }
 296
 297     update_state(s);
 298 }
 299
 300 static void sifive_gpio_reset(DeviceState *dev)
 301 {
 302     SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
 303
 304     s->value = 0;
 305     s->input_en = 0;
 306     s->output_en = 0;
 307     s->port = 0;
 308     s->pue = 0;
 309     s->ds = 0;
 310     s->rise_ie = 0;
 311     s->rise_ip = 0;
 312     s->fall_ie = 0;
 313     s->fall_ip = 0;
 314     s->high_ie = 0;
 315     s->high_ip = 0;
 316     s->low_ie = 0;
 317     s->low_ip = 0;
 318     s->iof_en = 0;
 319     s->iof_sel = 0;
 320     s->out_xor = 0;
 321     s->in = 0;
 322     s->in_mask = 0;
 323 }
 324
 325 static const VMStateDescription vmstate_sifive_gpio = {
 326     .name = TYPE_SIFIVE_GPIO,
 327     .version_id = 1,
 328     .minimum_version_id = 1,
 329     .fields = (VMStateField[]) {
 330         VMSTATE_UINT32(value,     SIFIVEGPIOState),
 331         VMSTATE_UINT32(input_en,  SIFIVEGPIOState),
 332         VMSTATE_UINT32(output_en, SIFIVEGPIOState),
 333         VMSTATE_UINT32(port,      SIFIVEGPIOState),
 334         VMSTATE_UINT32(pue,       SIFIVEGPIOState),
 335         VMSTATE_UINT32(rise_ie,   SIFIVEGPIOState),
 336         VMSTATE_UINT32(rise_ip,   SIFIVEGPIOState),
 337         VMSTATE_UINT32(fall_ie,   SIFIVEGPIOState),
 338         VMSTATE_UINT32(fall_ip,   SIFIVEGPIOState),
 339         VMSTATE_UINT32(high_ie,   SIFIVEGPIOState),
 340         VMSTATE_UINT32(high_ip,   SIFIVEGPIOState),
 341         VMSTATE_UINT32(low_ie,    SIFIVEGPIOState),
 342         VMSTATE_UINT32(low_ip,    SIFIVEGPIOState),
 343         VMSTATE_UINT32(iof_en,    SIFIVEGPIOState),
 344         VMSTATE_UINT32(iof_sel,   SIFIVEGPIOState),
 345         VMSTATE_UINT32(out_xor,   SIFIVEGPIOState),
 346         VMSTATE_UINT32(in,        SIFIVEGPIOState),
 347         VMSTATE_UINT32(in_mask,   SIFIVEGPIOState),
 348         VMSTATE_END_OF_LIST()
 349     }
 350 };
 351
 352 static Property sifive_gpio_properties[] = {
 353     DEFINE_PROP_UINT32("ngpio", SIFIVEGPIOState, ngpio, SIFIVE_GPIO_PINS),
 354     DEFINE_PROP_END_OF_LIST(),
 355 };
 356
 357 static void sifive_gpio_realize(DeviceState *dev, Error **errp)
 358 {
 359     SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
 360
 361     memory_region_init_io(&s->mmio, OBJECT(dev), &gpio_ops, s,
 362             TYPE_SIFIVE_GPIO, SIFIVE_GPIO_SIZE);
 363
 364     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
 365
 366     for (int i = 0; i < s->ngpio; i++) {
 367         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[i]);
 368     }
 369
 370     qdev_init_gpio_in(DEVICE(s), sifive_gpio_set, s->ngpio);
 371     qdev_init_gpio_out(DEVICE(s), s->output, s->ngpio);
 372 }
 373
 374 static void sifive_gpio_class_init(ObjectClass *klass, void *data)
 375 {
 376     DeviceClass *dc = DEVICE_CLASS(klass);
 377
 378     device_class_set_props(dc, sifive_gpio_properties);
 379     dc->vmsd = &vmstate_sifive_gpio;
 380     dc->realize = sifive_gpio_realize;
 381     dc->reset = sifive_gpio_reset;
 382     dc->desc = "SiFive GPIO";
 383 }
 384
 385 static const TypeInfo sifive_gpio_info = {
 386     .name = TYPE_SIFIVE_GPIO,
 387     .parent = TYPE_SYS_BUS_DEVICE,
 388     .instance_size = sizeof(SIFIVEGPIOState),
 389     .class_init = sifive_gpio_class_init
 390 };
 391
 392 static void sifive_gpio_register_types(void)
 393 {
 394     type_register_static(&sifive_gpio_info);
 395 }
 396
 397 type_init(sifive_gpio_register_types)